Process of shrinking wood



at... a, 1934 1,981,567

UNITED STATES PATENT OFFICE 1,981,567 raocass or snnmxmo woon Alfred 6.01mi, Elkhorn, Wis.

No Drawing. Application June 20, 1932,

Serial No. 618,405

1 Claim. (CL 144409) The present invention is based on the discovery more resistant to heat; consequently the treated that in shrinking or compressing wood, it is unoil may be heated to a higher temperature withnecessary to treat the wood with any agent which out boiling during the step of saturation of the itself will solidity in the fibers or the wood or wood, thereby hastening such st p. Li w 5 which mixed with the fibers or cellular contents higher temperatures may be employed while the 60 of the wood will solidify, oil-saturated wood is under heat and pressure,

The object of my invention is to produce as hereinafter explained. From three to thirtyshrunk wood in a simple ec n i al and pracsix hours are required to saturate the wood detical manner without pre-boiling or steaming, p n n p n the Size Of h p c d i herand by which the wo d may be compressed either -acter. In some cases it may be desirable to force 65 longitudinally or transversely of the length of the Oil in e W d y pressure or by Other nown its fibers. By dispensing with pre-boiling or W yspre-steaming the wood in water and avoiding the I prefer the use of linseed oil as a softening use of h i l hi h digest or di l the agent and as a conductor for the heat later apwood tissues and cellular contents; I am enabled p i d because f its p n trating pr pe ti s; and 70 to produce a product in which the wood fibers are e au Since i does n s l d f except in xnot destroyed, but are compressed or collapsed tremely low temperatures d no pp tu y i together. Since my process makes it possible to iven f r oxidation, it may be expressed from the compress the wood both with and across the wood by p ssu av g a ha d homo eneous grain-I me ab1 d t produce for any given use cellulose mass. Any oil possessing similar char- 75 a piece of compressed wood most suitable for the acteristies ay be us d. purpose intended and required, The saturated piece of wood after removal The solidified or compressed wood produced from the oil bath is put in a heated press or mold by the process hereinafter described does not and pressure applied. The temperature of the shrink, swell or warp with changes in atmosmold or press is kept below the point at which so pheric conditions. Neither does it splinter nor the oil in the wood will vaporize. The oil acts split. It may be worked and polished. The as a conductor of the heat from the press or processed wood finds use in tools, as bearings and mold and from the surface of the wood to the as lining in machinery'where metal cannot work interior of the wood. During the heating and or is dangerous to use as in oilpumps or in other pressing, the wood is in a semi-plastic state. 5 machinery or equipment handling oil, gas, or The pressure applied is sufficient to compress the explosives. Since it does not split or rough on wood to a solid state so that there are no spaces the cross grain, the processed wood is well adaptbetween the fibers, and so that the cell walls are ed for use as gears'or as loom shuttles. It also collapsed.

makes desirable flooring. For this purpose while In shrinking the wood lengthwise of its fibers 90 the wood is in a semi-plastic state during the or grain, the moving pressure is applied transprocess, as later described, it may be shaped in versely of the grain, the press or mold simulhexe-gohal Other Shaped dies and cut the taneously exerting a confining pressure at right proper thickness to simulate tile or mosaic angles to the applied pressure. In this case, a

40 flooring. piece of black walnut loses of its original 95 n h Preferred manner of Practicing y thickness; red cedar, willow and elm vention, I take a block of natural hard or soft T hrink th wood at right angles to the grain, wood and immerse it in raw or boiled linseed oil. a funnel-shaped mold is employed ith pressure As a precaution, the linseed oil is prepared by applied from above to force the semi-plastic mass 45 cl ans g it of solid matter and of sediment by into a narrower compass. The wood may thus be mixing t W h 3% or thereabouts in volume of reduced to two-thirds or less of its original diamcarbolic acid or other suitable cleansing agent t r and allowing the solids, sediment, and acid to After cooling the solidified and shrunk wood I settle to the bottom of the container. The may be removed from the mold without mechan- 0 cleansed linseed oil may then be mixed with 1% ical assistance. Wood processed as I have den Weight of Sodium o i h W Od is scribed possesses great strength and durability. soaked to saturation in the oil. To hasten the Black walnut so processed withstands an end process of saturation the oil is warmed, care thrust or crush test of 17,000 pounds per square being taken to prevent boiling. Experiments inch; elm, 24,000 pounds. The tensile strength 55 have shown that sodium chloride renders the oil is also increased. The weight, however, of a piece of treated wood is about the same as in its by the simultaneous application oi heat and of original state. pressure applied both transversely and longitudi- I claimznally of the grain of the wood; removing the heat The process oi shrinking wood comprising the and continuing the application of such pressure 6 following steps: saturating the wood by immeruntil the wood is cool; thereafter removing the 30 sion in a bath hot but not boiling linseed oil wood from the pressure applying means.

containing sodium chloride; thereafter expressing the oil from the wood and collapsing its fibers l ALFRED G. OLSEN. no s 5d it'll)? so e5 no so v ass 

